Method and apparatus to automatically determine type of gun connected to a wire feeder

ABSTRACT

A process is disclosed that monitors a characteristic of a welding gun connected to a wire feeder and, based on the detected characteristic, automatically determines the type of gun connected and sets operating parameters of the wire feeder and/or welding gun accordingly.

BACKGROUND OF INVENTION

The present invention relates generally to welding systems and, moreparticularly, to a method and apparatus of automatically determining thetype of gun or torch connected to a wire feeder or other component of awelding-type system. Moreover, the present invention relates toautomatic setting of operating parameters of a welding-type system basedon the type of component connected.

MIG welding, formerly known as Gas Metal Arc Welding (GMAW), combinesthe techniques and advantages of TIG welding's inert gas shielding witha continuous, consumable wire electrode. An electrical arc is createdbetween the continuous, consumable wire electrode and a workpiece. Assuch, the consumable wire functions as the electrode in the weld circuitas well as the source of filler metal. MIG welding is a relativelysimple process that allows an operator to concentrate on arc control.MIG welding may be used to weld most commercial metals and alloysincluding steel, aluminum, and stainless steel. Moreover, the travelspeed and the deposition rates in MIG welding may be much higher thanthose typically associated with either Gas Tungsten Arc Welding (TIG) orShielded Metal Arc Welding (stick) thereby making MIG welding a moreefficient welding process. Additionally, by continuously feeding theconsumable wire to the weld, electrode changing is minimized and assuch, weld effects caused by interruptions in the welding process arereduced. The MIG welding process also produces very little or no slag,the arc and weld pool are clearly visible during welding, and post-weldclean-up is typically minimized. Another advantage of MIG welding isthat it can be done in most positions which can be an asset formanufacturing and repair work where vertical or overhead welding may berequired.

A wire feeder is typically used to deliver welding wire to a weld.Generally, the wire feeder includes a spool of welding wire that istranslated by a drive assembly from the wire feeder to a welding gunwhereupon the welding wire is introduced to the weld. Operation of thewire feeder is typically governed by a combination of control signalsfrom the power source, user inputs, and feedback received from the weld.For example, wire feeders have been designed to automatically adjust therate by which welding wire is delivered to the weld so as to maintaineither a constant voltage or constant current level at the weld. Forexample, the higher the rate or wire feed speed, the higher theamperage.

Most wire feeders include an output terminal designed to receive aconnecting cable from the welding gun. Typically, the output terminal isa receptacle designed to receive a pinned connector attached to thewelding gun. In operation, uni- or bi-directional control signals arepassed from the gun and wire feeder across the connecting pins andassociated control cable. Some wire feeders are designed to work with adedicated gun type while other wire feeders may be connected to multipletypes of welding guns. For those wire feeders that are applicable withmore than one type of welding gun, it is incumbent upon the userinteractively to adjust or set the operating parameters on the wirefeeder setup menu appropriately. If the operating parameters and thewelding gun connected to the wire feeder are mismatched, the weldingprocess may be negatively affected and/or cause damage to either thewire feeder or welding gun, or both.

It would therefore be desirable to have a method and apparatus toautomatically determine the type of gun connected to the wire feeder. Itwould also be desirable to have a system whereby operating parameters ofthe welding system are automatically set or selected based on the typeof welding gun connected to the wire feeder.

BRIEF DESCRIPTION OF INVENTION

The present invention is directed to a system designed to automaticallydetermine the type of gun or other component connected to a wire feederor other welding-type apparatus that overcomes the aforementioneddrawbacks. A control process is disclosed that monitors a physicalcharacteristic of a welding gun connected to a wire feeder and, based onthe detected physical characteristic, automatically sets operatingparameters of the wire feeder and/or welding gun. For example, when thewelding gun is connected to the wire feeder assembly, the type of pinconfiguration is first determined. From the number of pins, a furtherdetermination is made, based on an impedance of a motor, electricalcircuit, or digital signature in the welding gun, to determine the typeof gun connected. Based on that which is detected, operating parametersof the wire feeder as well as the welding gun are set.

Therefore, in accordance with one aspect of the present invention, awire feeder is disclosed and includes an output connectable to a gunassembly. The wire feeder further includes a controller configured toautomatically determine gun assembly type when the gun assembly isconnected to the output.

In accordance with another aspect of the present invention, a controllerfor a welding-type system is configured to detect an impedance of amotor assembly designed to deliver welding wire to a weld. Thecontroller is further configured to determine, from the impedance, atype of load placed on the motor assembly and, based on the type ofload, automatically set an output mode of the motor assembly.

According to yet another aspect of the present invention, a method ofcontrolling operation of a wire feeder includes the step of determiningconfiguration of pins in a connector connecting a welding gun to a wirefeeder. From the configuration of pins, an output mode of a motorassembly in the wire feeder is automatically set.

In accordance with yet a further aspect of the present invention, a wirefeeder includes means for determining a type of welding gun connected todeliver welding wire to a weld and means for automatically setting anoutput mode of a motor drive assembly based on the type of welding gun.

Various other features, objects and advantages of the present inventionwill be made apparent from the following detailed description and thedrawings.

BRIEF DESCRIPTION OF DRAWINGS

The drawings illustrate one preferred embodiment presently contemplatedfor carrying out the invention.

In the drawings:

FIG. 1 is a pictorial view of a welding system in accordance with oneaspect of the present invention.

FIG. 2 is a perspective view of a push-pull-type MIG welding gun for usewith the welding system illustrated in FIG. 1.

FIG. 3 is a perspective view of a standard MIG welding gun for use withthe welding system illustrated in FIG. 1.

FIG. 4 is a perspective view of a spool-type MIG welding gun for usewith the welding system illustrated in FIG. 1.

FIG. 5 is a flow chart setting forth the steps of a gun detectionalgorithm in accordance with the present invention.

DETAILED DESCRIPTION

The present invention will be described with respect to a gun detectionand parameter setting process that automatically determines the type ofwelding gun connected to a wire feeder of a welding system. One skilledin the art, however, will appreciate that the present invention mayequivalently be used for the detection of other welding componentsconnected to a wire feeder or other apparatus of a welding system.Further, the present invention is also applicable for other high poweroutput systems such as plasma cutting systems and induction heatingsystems.

Referring to FIG. 1, a welding-type system 10 is show incorporating thepresent invention. System 10 includes a portable power source 12, whichcan be an AC or a DC welding power supply operable in either a constantcurrent (CC) or constant voltage (CV) mode. The power source 12 has awork cable 14 and clamp 16 designed to hold a workpiece 18 for welding.Power source 12 is also;

-   -   connected to a wire feeder 20 via an input power cord or cable        21. Cable 21 is designed to translate power from the power        source 12 or other power supply to the wire feeder. Also        connected between the power source 12 and the wire feeder 20 is        a weld cable 22. The wire feeder 20 also includes a welding        torch or gun 24 and a voltage sensing lead 25 with clip 26        configured to provide voltage at the weld feedback to the wire        feeder and/or power source. A shielding gas cylinder 28 is also        connected to the wire feeder 20 to provide shielding gas through        hose 29 for the welding process. Alternately, the wire feeder 20        may be disposed in the power source 12 to provide an integrated        MIG welder.

The wire feeder 20 includes a wire drive assembly 30 that includes aspool of welding wire (not shown) that is supplied to the weld undercontrol of a controller 32 that is connected to the power source 12through cord 22. The controller is governed by a microprocessor capableof being programmed to operate according to certain algorithms and/orprograms. User selections or inputs received by the controller from adisplay and control panel 34 and an internally programmed algorithmcause welding system 10 to operate according to the user selections. Forexample, the wire feeder includes an output terminal or receptacle 36that is designed to receive a pin connector 37 designed to engage theoutput terminal. The pin connector 37 is connected to gun 24 via cable38.

When the welding torch 24 is positioned proximate to workpiece 18,welding wire is fed into contact with the workpiece 18. Once triggered,an electrical current and voltage are generated to cause the weldingwire to be heated and melt. As a result, an electrical arc isestablished which causes the welding wire to continue to melt as well astransfer the melted welding wire to the workpiece 18 where the weldingwire fuses and cools with the workpiece 18. Because the electricalenergy supplied to the welding system is typically greater than thatrequired to melt the welding wire, most of the remaining energy is inthe form of heat which is transferred to the surface of the workpiece 18resulting in the workpiece 18 also melting and improved bonding betweenthe melted welding wire and the workpiece 18. As the welding torch 24 istranslated across the workpiece 18, melted welding wire is continuouslytransferred to the workpiece 18.

The power source is designed to operate in either a CC or CV mode. Thewire feeder is also designed to introduce flux cored, solid steel, orstainless steel welding wire to a weld. One skilled in the art wouldappreciate that the present invention is equivalently applicable withother welding systems having different operating specifications andother consumable types.

Referring now to FIG. 2, welding gun 24 is perspectively illustrated.Welding gun 24 is an exemplary push-pull type of welding gun thatincludes an internal motor and drive assembly 40 designed to pullwelding wire from the wire feeder or other welding wire source. As willbe described in greater detail below, the illustrated push-pull weldinggun is an example of only one type of welding gun or torch that may beapplicable with the present invention. That is, other types of weldingguns are contemplated for use with the welding system illustrated inFIG. 1 in accordance with the present invention.

As indicated previously, welding gun 24 is a push-pull type of weldingcomponent that utilizes an internal motor and drive assembly 40 to pullwire from a wire feeder or; other source of welding wire. The weldinggun may be air cooled or liquid cooled. As will be further described,welding gun 24 is typically connected to the wire feeder with a 10-pinconnector. Welding gun 24 is defined by a gun body 42 that is connected,or integrally formed, with barrel 44. At one end of barrel 44 is acontact tip 46 that, as described above, is used to initiate a weldingarc. Tip 46 is centrally disposed within nozzle 48 which is connected toa nozzle adaptor 50. The nozzle and nozzle adaptor may be rotated so asto adjust the position of the tip relative to the nozzle. That is, thetip may be repositioned to extend beyond the end of the nozzle or,alternatively, be repositioned to extend entirely within the nozzle.Welding gun 24 also includes a handle 47 having a trigger mechanism 48operationally mounted thereto. As discussed above, when the trigger isdepressed, an electrical current and voltage are generated to cause thewelding wire to be heated and melt. As a result, an electrical arc isestablished which causes the welding wire to continue to melt as well astransfer the melted welding wire to the workpiece.

Referring now to FIG. 3, another type of welding gun 51 that may beconnected to the wire feeder illustrated in FIG. 1 is shown. Welding gun51 is a conventional MIG welding gun that is used to initiate andmaintain welding of a consumable to a workpiece. Welding gun 51 is alsodefined by a gun body 52 having a handle 54 and trigger mechanism 56. Incontrast to the push-pull gun 24 illustrated in FIG. 2, welding gun 51typically includes a 4-pin connector. Similar to welding gun 24, weldinggun 51 includes a barrel 58 that is connected to a welding nozzle 60having a tip disposed therein 62. Unlike the push-pull type of weldinggun illustrated in FIG. 2, welding gun 50 does not include a separatemotor and drive assembly to pull welding wire from the wire source. Inthis regard, welding gun 51 is designed to simply receive the weldingwire being pushed by the drive and motor assembly within the wire feederand deliver that welding wire to the weld.

Referring now to FIG. 4, another type of welding gun is shown. Weldinggun 64 is typically considered a spool-type gun that includes anindependent source of welding wire housed within an internal spool 66.Wire is introduced to the weld from the internal spool 66 by a motor anddrive assembly 68 disposed within the gun handle 70. Disposed on handle70 is a triggering mechanism 72 that, similar to the previouslydescribed welding guns, commences the welding process when depressed bya user. Similar to the welding guns of FIGS. 2 and 3, welding gun 64includes a barrel 74 that is connected to a nozzle 76 having a contacttip 78 disposed therein. Additionally, similar to the push-pull weldinggun of FIG. 2, welding gun 64 typically includes a 10-pin connector forconnection to an output terminal of a wire feeder.

Referring now to FIG. 5, the steps of a control algorithm forautomatically determining the type of welding gun connected to a wirefeeder and setting operating parameters of the wire feeder based on thedetermined gun type is illustrated. For purposes of illustration and notlimitation, the control algorithm will be described with respect todelineation between a standard MIG gun such as that described withrespect to FIG. 3, a spool-type gun such as that described with respectto FIG. 4, and a push-pull-type gun such as that described with respectto FIG. 2. However, the present invention is equivalently applicablewith the detection of other types of welding guns or other weldingcomponents.

Process 80 begins at 82 with the connection of a welding gun or othercomponent to be automatically detected to the wire feeder of a weldingsystem. When the user depresses the trigger on the handle of the weldinggun or otherwise provides a signal indicative of commencement of thewelding process, e.g. connection of a serial link between the weldinggun and the wire feeder, an input is received at 84. From the input 84,algorithm 80 determines at 86 whether the input was received across a4-pin or a 10-pin connector. If the input was received across a 4-pinconnector 86, 88, a controller in the wire feeder automatically enablesthe wire feed motor in the wire feeder in a constant speed mode at 90.On the other hand, if the controller executing algorithm 80 determinesthat the input was received across a 10-pin connector 86, 92, adetermination is made at 94 whether an impedance of a motor in thewelding gun is equal to that of a spool-type gun.

In one exemplary embodiment, the controller compares the measuredimpedance to a look-up table of values to determine if the input wasreceived from a spool gun. In a further embodiment, the look-up tablemay also include values delineating between the type of spool guns thatmay be connectable to the wire feeder. If, based on a comparison betweenthe measured impedance and values contained in one or more look-uptables, the impedance of the feed motor in the welding gun correspondsto that of a spool gun 94, 96 then the motor in the gun is enabled in aconstant speed mode at 98. Alternately, characteristics of an electricalcircuit or digital signature in the gun may be matched with values in alook-up table to determine the type of gun connected. In this regard, itis determined that a spool gun has been connected to the wire feederand, accordingly, operating parameters of the spool gun areautomatically set based on the determination made at 94. In contrast, ifthe impedance of the feed motor does not equal that of a spool-type gun94, 100, a conclusion is then made that a push-pull type of welding gun,such as that described with respect to FIG. 2, is connected to the wirefeeder. Accordingly, the motor within the push-pull welding gun isenabled in a constant speed mode at 102. Further, the wire feed motor inthe wire feeder is enabled in a constant torque mode. In this regard,the motor assembly within the push-pull welding gun will pull wire fromthe wire feeder or other wire source at a constant speed whereas thewire feed motor in the wire feeder is enabled to maintain a constanttorque on the wire being pushed to the welding gun. Once a determinationis made whether the welding gun is a standard MIG gun, a spool-type gun,or a push-pull-type gun, algorithm 80 concludes at 106.

One skilled in the art will readily appreciate that the presentinvention may also be implemented to delineate between types of standardMIG guns, spool-type guns, and push-pull-type guns. That is, while FIG.5 has been described with respect to delineating between a push-pullgun, a standard MIG gun, and a spool-type gun, process 80 may also beimplemented to differentiate between various types of push-pull guns,spool-type guns, or conventional MIG welding guns. For example, onceprocess 80 concludes that a push-pull-type gun is connected to the wirefeeder, a further determination may be made to determine whether acertain type of push-pull-type gun is connected. In this furtherembodiment, the impedance or some other characteristic of the motor inthe push-pull gun may be examined and compared to a set of values in alook-up table to determine the type of push-pull welding gun. Based onthe type of push-pull welding gun determined, the operating parametersof the motor in the gun as well as the motor in the wire feeder may beset to a value more tailored to the type of push-pull gun connected tothe wire feeder. Further, the look-up table is preferably stored involatile memory that may be updated as new gun types and models aredeveloped.

As one skilled in the art will fully appreciate, the heretoforedescription of welding devices not only includes welders, but alsoincludes any system that requires high power outputs, such as heatingand cutting systems. Therefore, the present invention is equivalentlyapplicable with any device requiring high power output, includingwelders, plasma cutters, induction heaters, and the like. Reference towelding power, welding-type power, or welders generally, includeswelding, cutting, or heating power. Description of a welding apparatusillustrates just one embodiment in which the present invention may beimplemented. The present invention is equivalently applicable with manyhigh power systems, such as cutting and induction heating systems, orany similar systems.

Therefore, in accordance with one embodiment of the present invention, awire feeder is disclosed and includes an output connectable to a gunassembly. The wire feeder further includes a controller configured toautomatically determine gun assembly type when the gun assembly isconnected to the output.

In accordance with another embodiment of the present invention, acontroller for a welding-type system is configured to detect animpedance of a motor assembly designed to deliver welding wire to aweld. The controller is further configured to determine, from theimpedance, a type of load placed on the motor assembly and, based on thetype of load, automatically set an output mode of the motor assembly.

According to yet another embodiment of the present invention, a methodof controlling operation of a wire feeder includes the step ofdetermining a configuration of pins in a connector connecting a weldinggun assembly to a wire feeder. From the configuration of pins, an outputmode of a motor assembly in the wire feeder is automatically set.

In accordance with yet a further embodiment of the present invention, awire feeder includes means for determining a type of welding gunconnected to deliver welding wire to a weld and means for automaticallysetting an output mode of a motor drive assembly based on the type ofwelding gun.

The present invention has been described in terms of the preferredembodiment, and it is recognized that equivalents, alternatives, andmodifications, aside from those expressly stated, are possible andwithin the scope of the appending claims.

1. A wire feeder comprising: an output connectable to a gun assembly; acontroller configured to automatically determine a type of gun assemblyconnected to the output; a motor assembly configured to deliver aconsumable electrode to a weld when the gun assembly is activated; andwherein the controller is further configured to determine gun assemblytype based on an impedance of a motor assembly in the gun when the gunassembly is first activated.
 2. The wire feeder of claim 1, wherein thecontroller is further configured to determine gun assembly type when atrigger of the gun assembly is depressed.
 3. The wire feeder of claim 1,wherein the controller is further configured to determine gun assemblytype when a serial communication link is established with a power sourceor wire feeder.
 4. The wire feeder of claim 1, wherein the controller isfurther configured to compare the impedance to a look-up table ofimpedance value; to determine gun assembly type.
 5. The wire feeder ofclaim 1, wherein the motor assembly is further configured to deliver aconsumable electrode to the weld at a constant speed if a four-pinconnector is connected to the output.
 6. The wire feeder of claim 5,wherein the motor assembly is further configured to deliver a consumableelectrode to the weld at a constant torque if a ten-pin connector of thegun assembly is connected to the output.
 7. The wire feeder of claim 6,wherein the controller is further configured to cause a motor in the gunassembly to deliver a consumable electrode to a weld at a constant speedif a ten-pin connector of the gun assembly is connected to the output.8. The wire feeder of claim 1, wherein the output is ether configured toreceive a connector of a MIG welding gun, a spool gun, or a push-pullwelding gun.
 9. A controller for a welding-type system, the controllerconfigured to: detect an impedance of a motor assembly designed todeliver welding wire to a weld; from the impedance, determine a type ofload placed on the motor assembly; and based on the type of load,automatically set an output mode of the motor assembly.
 10. Thecontroller of claim 9, wherein the type of load is indicative of a gunassembly operationally connected to the motor assembly.
 11. Thecontroller of claim 9, wherein the output mode includes one of constantspeed mode and constant torque mode with at least one feedback path tothe motor assembly.
 12. The controller of claim 11, further configuredto set the output mode to the constant speed mode if the type of load isa spool-type gun.
 13. The controller of claim 11, further configured toset the output mode to the constant speed mode if the type of load is apush-pull type welding gun.
 14. The controller of claim 9, furtherconfigured to determine a number of pins in a connector of a welding gunoperationally connected to a wire feeder having the motor assemblydisposed therein.
 15. A method of controlling operation of a wirefeeder, the method comprising the steps of: determining configuration ofpins in a controller connecting a welding gun assembly to a wire feeder:from the configuration, automatically setting an output mode of a motorassembly in the wire feeder; and determining an impedance of a gun motorassembly disposed in the welding gun assembly and setting the outputmode of the gun motor assembly based on the impedance.
 16. The method ofclaim 15, wherein the output mode of the gun motor assembly includes aconstant speed mode if the impedance matches that of a spool gun. 17.The method of claim 15, further comprising the step of setting theoutput mode of the motor assembly to a constant torque mode if theconfiguration of pins corresponds to a push-pull welding gun assembly.18. The method of claim 17, further comprising the step of setting theoutput mode of the gun motor assembly to a constant speed mode if theconfiguration of pins corresponds to a push-pull welding gun assembly.19. An apparatus comprising: a wire feeder defined by a plurality ofside panels, a cover panel, and a base; a motor disposed in the wirefeeder and configured to drive a spooled wire to a weld; an outputterminal connected to a surface of the wire feeder and configured toelectrically connect the wire feeder to a welding-type component; and acontroller configured to automatically determine a type of gun assemblyconnected to the output terminal.
 20. The apparatus of claim 19, whereinthe controller it further configured to determine gun assembly typebased on an impedance of a motor assembly in the gun when the gunassembly is first activated.
 21. The apparatus of claim 20, wherein thecontroller is further configured to compare the impedance to a look-uptable of impedance values to determine gun assembly type.
 22. Theapparatus of claim 20, wherein the motor assembly is further configuredto deliver a consumable electrode to the weld at a constant speed if afour-pin connector is connected to the output terminal.
 23. Theapparatus of claim 20, wherein the motor assembly is further configuredto deliver consumable electrode to the weld at a constant torque if aten-pin connector of the gun assembly is connected to the outputterminal.
 24. The apparatus of claim 19 wherein the output terminal isfurther configured to receive a connector of a MIG welding gun, a spoolgun, or a push-pull welding gun.
 25. The apparatus of claim 19 whereinthe controller is further configured to determine gun assembly type whena serial communication link is established with a power source.
 26. Theapparatus of claim 19, wherein the controller is further configured todetermine gun assembly type when a trigger of the gun assembly isdepressed.